While the lesson focuses on right triangles, this activity offers a great way to practice the area of all triangles through an interactive webpage. The activity begins with the class taking a square paper and cutting in in half; can they...

Pupils figure out how to be resourceful when tasked with finding the area of a triangle knowing nothing but its endpoints. Beginning by exploring and decomposing a triangle, learners find the perimeter and area of a triangle. They...

Combine algebraic and geometric strategies to find solutions. The task asks learners to find the coordinates of a third vertex of a triangle to create a triangle with a specific area. The project is a set of seven problems that...

What makes an equilateral triangle equilateral? It turns out it's much more than just the side lengths! Learners analyze four different triangles to determine the best equilateral triangle. They create a formula that they later use to...

No height? No problem! Learners use their knowledge and a little help from GeoGebra to develop the Law of Sines formula. The Law of Sines helps to determine the height of triangles to calculate the area.

Teach your pupils to calculate the area of different polygons. Learners create formulas to solve their problems. They use the TI navigator to graph their shapes and observe the change in area.

What do you do when you don't think you have enough information? You look for another way to do the problem! Pupils combine what they know about finding the area of a triangle and trigonometry to determine triangle area when they don't...

Not all structures take the shape of a polygon. The 21st lesson plan in a series of 29 shows young mathematicians they can create polygons out of composite shapes. Once they deconstruct the structures, they find the area of the composite...

It's always nice to have a plan B. Pupils investigate an alternate formula for the area of a triangle that uses sine. A set of challenge questions shows how the new formula relates to the well-known formula of (1/2)bh.

How many sides does that polygon have? Building directly from lesson number eight in this series, learners now find the area and perimeter of any polygon on the coordinate plane. They decompose the polygons into triangles and use Green's...

The problem seems simple: find the area of the equilateral triangle whose sides are each length 1. In fact, this same problem is solved in 8th grade, addressing a different Common Core standard, using the formula for area of a triangle...

Students solve the area of triangles. In this precalculus lesson plan, students are given two sides of a triangle and asked to calculate the area. They apply the law of sine and the side-angle-side area formula to solve.

Your algebra learners emphasize the"geometric" in geometric series as they use a common ratio between algebraic terms and find that it corresponds to a repeated similarity transformation. 

Evaluate different aspects of geometry with one task. An assessment activity prompts learners to determine the area of a pathway in the shape of a parallelogram. The Pythagorean Theorem and area formulas for various polygons provide the...

Students explore volume and surface area. In this math activity, students fill boxes with cubes to identify the volume of the boxes. Students discuss area.

This is an interesting geometry problem. Given the figure, find the area of a triangle that is created by the intersecting lines. The solution requires one to use what he/she knows about coordinate geometry, as well as triangle...

When algebra and geometry get together, good things happen! Given a system of inequalities that create a quadrilateral, learners graph and find vertices. They then use the vertices and Green's Theorem to find the area and perimeter of...

Learn how to calculate the length and midsegments of triangles. Young scholars differentiate between similar and congruent triangles. They create a spreadsheet with their findings.

Young scholars calculate the area of different polygons. For this geometry lesson, students find the area of complex polygons. They solve word problems using rates and distances.

Learners calculate the area of different polygons. In this geometry lesson, students find the area for trapezoids, rhombuses and kites.

Young mathematicians represent a triangle with a matrix and use the determinant to find the area of three given triangles. Learners also verify the formula for area of a triangle. 

Middle and high schoolers investigate all the different places in math that square root is present. In this geometry activity, pupils discuss square roots as it relates to a right triangle and construction. They go over altitude, rise,...

Eighth graders practice calculating the perimeter of different shapes. As a class, they work together to calculate the area of rectangles and triangles using the proper formula. To end the lesson, they determine how many feet are in a...

Students use models and symbols to represent properties of the Pythagorean Theorem. In this right triangle lesson, students connect real jobs to properties of right triangles. They solve word problems applying the correct ratios and...